Supposed rare early submariner inherited, please tell me more!!!

[EGP]

I have a rolex submariner oyster perpetual which I am having trouble identifying. It is a tiffany and co. marked watch. It does not seem to have the 'maxi dials', and I am told that the watch is from the fifties. I have read that there is significance in the depth rating, which reads 200m-360ft m and ft are in itallics if this is significant). apparently earlier and more valuable watches have the m reading before the ft, and importantly I cannot seem to find any other watches with similar depths specified (oddly 200m is not 360ft, is there some explaination?). It does have the mercedes hour hand. At the very bottom it says 'SWISS'. On the twisty dial it has minute markings up until 15 minutes, and from then on regular five minute markings to the hour.
When I got it, it was completely dead, as it had been in my grandfather's sock drawer since the 70s, and the metal strap had snapped off. The little insert on the top of the twist-dial had fallen out, and the dial was very difficult to turn. The screen was so scratched you could barely read the text under, and was yellow with age, while all of the metal was very dull and had tears of dirt in all of the cracks. I brought it to rolex (all of the shop attendants were immediately called over to have a look and there was much ooing and aahing at the old broken watch) who recommended I re-polish the whole item, and replace the screen and insert, as well as restoring all of the seals and mechanism.
From top to bottom the text reads
(rolex crown logo)
ROLEX
oyster perpetual
(watch hands)
Tiffany & CO.
200m - 360 ft
SUBMARINER
SUPERLATIVE CHRONOMETER
OFFICIALLY CERTIFIED
(and at the very bottom- SWISS)
I don't really want to sell it at all, but am VERY interested in hearing opinions, the value of and the history of the watch. I am new to rolex by the way.